Liquid crystal display apparatus containing image sensor and process for producing the same

ABSTRACT

A liquid crystal display apparatus containing an image sensor, which comprises a liquid crystal display part comprising an active matrix circuit, a peripheral driver circuit for driving the active matrix circuit, and a sensor part, integrated on one substrate, wherein the sensor part is sealed and protected with a sealing part and a counter substrate.

This application is a divisional of U.S. application Ser. No. 11/641,516filed Dec. 19, 2006 now U.S. Pat. No. 7,528,912 which is a continuationof U.S. application Ser. No. 11/140,700 filed May 31, 2005 (now U.S.Pat. No. 7,158,199 issued Jan. 2, 2007) which is a continuation of U.S.application Ser. No. 10/743,482, filed on Dec. 22, 2003 (now U.S. Pat.No. 6,937,306 issued Aug. 30, 2005) which is a continuation of U.S.application Ser. No. 10/288,958, filed on Nov. 6, 2002 (now U.S. Pat.No. 6,680,764 issued Jan. 20, 2004) which is a divisional of U.S.application Ser. No. 09/143,109, filed on Aug. 28, 1998 (now U.S. Pat.No. 6,496,240 issued Dec. 17, 2002).

FIELD OF THE INVENTION

The present invention relates to an integrated liquid crystal displayapparatus having a function of an image sensor, and particularly itrelates to the constitution of an image sensor part.

BACKGROUND OF THE INVENTION

A liquid crystal panel, in which a liquid crystal is oriented byapplying a voltage to a liquid crystal layer from pixel electrodes, toform an image on a display part, has been known.

A constitution of a conventional liquid crystal panel is brieflydescribed below.

An element substrate comprises an insulating substrate having thereon adisplay part comprising thin film transistors and a peripheral circuit.The element substrate and a counter substrate are adhered by a sealingmaterial with ensuring a gap between the substrates by a spacer. Aliquid crystal is contained between the element substrate and thecounter substrate.

The liquid crystal is sandwiched by the pair of substrates andsurrounded by the sealing part.

As shown in FIG. 2, the sealing part of the panel is arranged tosurround the display part or the display part and the peripheral drivercircuit.

In the conventional constitution, the element substrate means asubstrate in which an active matrix circuit and the peripheral circuitare provided. The counter substrate arranged as facing the elementsubstrate, in which a counter electrode and a color filter are provided.

In the conventional constitution, a resin for sealing having anultraviolet setting property or a thermosetting property is used as thesealing material.

An image sensor, on the other hand, has been widely used as an opticalsensor converting an image to an electric signal in a copying machine, adigital still camera, a video camera and a facsimile machine.

Recently, a miniature system for incorporating an image and displayingthe image is demanded. As a constitution meeting such a demand, a liquidcrystal display device with which a sensor module such as a CCD isintegrated is considered, but there are problems in consumption power(about 5 W), production cost and size.

The inventors of the invention intend to produce a liquid crystal paneland an image sensor on one substrate by using a MOS thin filmtransistor.

By using such a constitution, the apparatus can be miniaturized and of alow consumption power (about 50 mW) and low cost.

In the case where a liquid crystal panel and an image sensor areproduced on one substrate, the arrangement of the panel and the imagesensor and the constitution of the seal become important issue.

An object of the invention is to provide a liquid crystal display panelhaving a display part and an image sensor on one substrate, which hashigh reliability and an image sensor of low cost.

SUMMARY OF THE INVENTION

The structure of the liquid crystal panel shown in FIG. 1B correspondsto those shown in FIGS. 4A and 4B.

The invention relates to, as a first aspect, a liquid crystal displayapparatus comprising a liquid crystal display part comprising an activematrix circuit, a peripheral driver circuit for driving the activematrix circuit, and a sensor part, integrated on one substrate, whereinthe sensor part 120 has a sealed space 307 sealed by a sealing part 104and a counter substrate 302. By employing such a constitution, thesealed space is completely shielded from an external atmosphere by thesubstrates and the sealing part.

Furthermore, the counter substrate may be adhered in an inert gasatmosphere to fill the sealed space with an inert gas (such as Ar andN₂), so as to prevent deterioration of the sensor part due to a reactionwith oxygen contained in the air.

By sealing the sensor part with the sealing part and the countersubstrate, an effect is obtained in that inclusion of the liquid crystaland dusts into the sensor part and a damage such as a flaw of the sensorpart occurring on an injection step of the liquid crystal can beprevented.

The invention relates to, as a second aspect shown in FIG. 1A, a liquidcrystal display apparatus comprising a liquid crystal display partcomprising an active matrix circuit, a peripheral driver circuit 111 fordriving the active matrix circuit, and a sensor part 120, integrated onone substrate,

wherein the sensor part 120 is surrounded by at least one sealing part104, and

a sealing part 103 provided between the liquid crystal display part andthe sensor part seals the liquid crystal and protects the sensor part.

By employing such a constitution, inclusion of the liquid crystal anddusts, generation of static charge, and an external impact can beprevented in the sensor part after the adhering step.

Alternatively, as shown in FIGS. 1B, 4A and 4B, the sensor part may bedoubly surrounded by plural sealing parts. The outer sealing partfunctions as a dummy seal. By employing such a constitution, the sensorpart 120 can be further prevented from dusts, static charge and externalpressures, and the distance between the substrates can be sufficientlymaintained. The sensor part may further be surrounded by plural sealingparts in three times, four times or more, or plural sealing parts may bearranged as a dummy seal outside the sealing part of the sensor part.

The invention relates to, as a third aspect, a liquid crystal displayapparatus comprising a liquid crystal display part comprising an activematrix circuit, a peripheral driver circuit for driving the activematrix circuit, and a sensor part, integrated on one substrate, whereina spacer 306 is not present in the sensor part. When the number of thespacers in the sensor part is larger than that in the liquid crystalpart, they becomes obstacles upon incorporating an image. Thus, as shownin FIG. 4B, it is preferred that no spacer is present between a receptorof the sensor part and the counter substrate. By employing such aconstitution, an image can be incorporated with good quality whileuniformly maintaining the distance between the substrates.

Since the sensor part is an element that reacts against external heat,it is preferred that the sensor part is arranged with a sufficientdistance to a heat generating circuit such as the peripheral drivercircuit, i.e., at a position that is less affected by heat.

By employing such a constitution, the sensor part can be protected fromexternal electrical influence, thermal influence and other physicalinfluence.

In the image sensor of the invention, as shown in FIG. 3A, photocarriers are generated by an amorphous silicon layer 352 having a largelight absorption coefficient to visible lights, and the readout of thesignals is controlled with a polycrystalline silicon TFT having a largemobility as a switching element.

In the invention, an image sensor formed by the thin film technique andthe thin film transistors constituting the display part are formed onone substrate, and an apparatus is obtained at low cost.

The display apparatus of direct vision type containing an image sensoris becoming large scale in future. The substrate is also becoming largescale due to a multi-panels substrate for reducing the production cost.

On the other hand, the sensor part, which is demanded to have a largenumber of pixels and a miniaturized optical system, is beingminiaturized to have a reduced pixel area, and therefore the differencein pixel area between the sensor part and the display part becomeslarge.

The invention relates to, as a fourth aspect, a liquid crystal displayapparatus comprising a liquid crystal display part comprising an activematrix circuit, a peripheral driver circuit for driving the activematrix circuit, and a sensor part, integrated on one substrate, whereina color filter formed on a counter substrate of the sensor part has acell size that is smaller than that formed on a counter substrate of thedisplay part, as shown in FIGS. 8A and 8B.

By employing such a constitution, a liquid crystal display panel can beobtained at low cost, in which the sensor part that has a small pixelarea and can incorporate an image with good quality is formed on thesame substrate as the liquid crystal display part.

The invention relates to, as a fifth aspect shown in FIG. 6B, a liquidcrystal display apparatus comprising a liquid crystal display partcomprising an active matrix circuit, a peripheral driver circuit fordriving the active matrix circuit, and a sensor part, integrated on onesubstrate, wherein the thickness d₁ of a counter substrate of the sensorpart is smaller than the thickness d₂ of a counter substrate of theliquid crystal display part.

By employing such a constitution, the influence on the optical systemattached to the sensor part can be reduced. The thinner the thickness ofthe counter substrate of the sensor part is, the less the light isrefracted, and thus the intensity of light can be maintained to obtain aliquid crystal display panel at low cost, in which the sensor part thathas a small pixel area and can incorporate an image with good quality isformed on the same substrate as the liquid crystal display part. Thethin counter substrate of the sensor part in the invention includescolorless transparent substrates or films and is not limited to a glasssubstrate or a quartz substrate.

The invention relates to, as a sixth aspect shown in FIG. 6C, a liquidcrystal display apparatus comprising a liquid crystal display partcomprising an active matrix circuit, a peripheral driver circuit fordriving the active matrix circuit, and a sensor part, integrated on onesubstrate, wherein the line width of the sealing part surrounding thesensor part is smaller than the line width of the sealing partsurrounding the liquid crystal display part.

By employing such a constitution, when a thin substrate is used in thesensor part, the sealing part can be prevented from inclusion in thesensor part, and the substrate can be prevented from cracking.

The invention relates to, as a seventh aspect shown in FIG. 6D, a liquidcrystal display apparatus comprising a liquid crystal display partcomprising an active matrix circuit, a peripheral driver circuit fordriving the active matrix circuit, and a sensor part, integrated on onesubstrate, wherein a counter substrate of the liquid crystal displaypart is maintained at a constant substrate distance by the sealing partand a spacer, and a counter substrate of the sensor part is in closecontact with the substrate by an adhesive 515.

By employing such a constitution, the sensor part can be completelyisolated from the external atmosphere, and deterioration due to contactwith the external atmosphere can be prevented. Because the space 507between the counter substrate and the element substrate of the sensorpart brings about refraction of light, the counter substrate and theelement substrate is preferably in as close contact therewith aspossible, as similar to the thickness of the counter substrate.

In order to have the fourth to seventh constitutions, precision isrequired in mating the sensor part having a small cell size and thecounter substrate on the step of adhesion to the counter substrate.Therefore, the counter substrate of the sensor part and the countersubstrate of the liquid crystal display part are adhered separately fromeach other.

The invention relates to a process for producing a liquid crystaldisplay apparatus containing an image sensor and comprising a liquidcrystal display part comprising an active matrix circuit, a peripheraldriver circuit for driving the active matrix circuit, and a sensor part,integrated on one substrate, the process comprising in this order

a step of adhering a counter substrate of the liquid crystal displaypart,

a step of cutting the counter substrate of the liquid crystal displaypart, and

a step of adhering a counter substrate of the sensor part.

As shown in FIGS. 6A to 6D, the display part and the sensor part areformed on one substrate, but the counter substrates 502 and 503 areseparated from each other in the display part and the sensor part.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are diagrammatic plan views showing the structures ofthe liquid crystal panels of the invention.

FIG. 2 is a diagrammatic plan view showing the structure of theconventional liquid crystal panel.

FIGS. 3A to 3D are fragmentary sectional views showing the productionstep in Example 1.

FIG. 4A is a plan view showing the structure of the liquid crystal panelof Example 1. FIG. 4B is a cross sectional view taken on line A-B ofFIG. 4A.

FIG. 5A is a diagrammatic plan view showing the structures of the liquidcrystal panels of Examples 2 to 3. FIG. 5B is a diagrammatic plan viewshowing the structure of the liquid crystal panel of Example 4.

FIGS. 6A to 6C are cross sectional views showing the structures of theliquid crystal panels of Examples 2 to 3 taken on line A-A_of FIG. 5A.

FIG. 6D is a cross sectional view showing the structure of the liquidcrystal panel of Example 4 taken on line B-B_of FIG. 5B.

FIG. 7 is a schematic perspective view showing an example of anapplication of the invention.

FIG. 8A shows a cell size of a color filter on a counter substrate of adisplay part while FIG. 8B shows a cell size of a color filter on acounter substrate of a sensor part.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention is described in more detail with reference to thefollowing examples, but the invention is not construed as being limitedthereto.

EXAMPLE 1

The production process of the panel is described by referring to FIGS.3A to 3C. The completion drawing is shown in FIGS. 4A, 4B and 1B.

An element substrate 301 is prepared.

In this Example, the element substrate 301 is a substrate shown in FIG.3A having an active matrix circuit and a peripheral circuit eachcomprising a TFT part, and a sensor part. The element substrate is notlimited if it has a pixel region and a peripheral circuit eachcomprising TFT elements.

The sensor part comprises a photoelectric conversion layer 352 and aphotoelectric conversion element.

The sensor part is formed simultaneously with the formation of the thinfilm transistors constituting the active matrix circuit and theperipheral circuit.

An oriented film (not shown in Figure) for the orientation of the liquidcrystal is coated on the element substrate and a counter substrate, andthen baked, followed by subjecting to a rubbing treatment.

A seal pattern and a dummy seal part are provided on the elementsubstrate with a sealing material 305 by using a seal printing machineor a seal dispenser, as shown in FIG. 3B. In this Example, while theseal pattern is provided on the element substrate, a step where the sealpattern is provided on the counter substrate may be employed.

As the constitution of each of the panels, the sealing part 103 isarranged to surround the display part 110 and the peripheral drivercircuit region 111. The sensor part is arranged to be surrounded by thesealing part 104.

A seal opening 107 is provided at least a part of the sealing part 103of the each of the panels, so as to be capable of injecting a liquidcrystal material from the opening to the inside of the sealing part.

A solution of an epoxy resin and a phenol hardening agent dissolved in aethyl cellosolve is used as the material for the sealing part in thisExample, but it is not particularly limited if it is a resin for sealinghaving an ultraviolet setting property or a thermosetting property.

Spacers 306 for maintaining the distance between the substrates arescattered selectively on the display part. Spherical bodies having adiameter of 5_m comprising a polymer series material, a glass seriesmaterial or a silica series material are used as the spacer.

The counter substrate 302 is prepared.

The counter substrate 302 is a substrate provided to be arranged asfacing the element substrate, on which a counter electrode and a colorfilter are provided.

The element substrate provided by the above-described steps and thecounter substrate are superimposed and adhered by heat press, as shownin FIG. 3C.

An injection inlet for a liquid crystal material is provided by acutting step using a scriber and a breaker, in such a manner that one ormore of the inlet is provided on a side where both of the edges of thepair of panels are matched.

Since a leader line of wiring is provided in this Example, the sidewhere the leader line is provided is also cut by a scriber.

A step of injecting the liquid crystal material 310 into the inside ofthe panels constituting the liquid crystal apparatus is conducted by avacuum injection method. The vacuum injection method is an injectionmethod for a liquid crystal material utilizing capillarity anddifference in pressure.

The liquid crystal material 310 is injected by the vacuum injectionmethod onto the pixel region and the peripheral driver circuit regioninside the sealing part of the panel through the injection inlet.

As the liquid crystal material, a nematic liquid crystal, a smecticliquid crystal, a cholesteric liquid crystal and other various liquidcrystals may be used. A nematic liquid crystal is used in this Example.

A pressure is applied to the panels from the both sides there of toexpel an excessive amount of the liquid crystal material, and withmaintaining the applied pressure, a sealing resin 118 of ultravioletsetting type or thermosetting type is coated on the injection inlet,followed by removing the pressure. Thus, the sealing resin is slightlydrawn into the inside of the injection inlet. The sealing resin ishardened in this state to seal the injection inlet, as shown in FIG. 3D.

A panel comprising a pair of substrates sandwiching a liquid crystal asshown in FIGS. 1B, 4A and 4B is obtained by the above-describedprocedures. Polarizers are attached on both sides of the panel, andwiring electrically connecting to the outside is provided, to completethe liquid crystal display apparatus.

An optical system is attached to the sensor part, to complete the liquidcrystal display apparatus containing an image sensor.

EXAMPLE 2

In this Example, the case where the counter substrate of the sensor partand the counter substrate of the display part are separated from eachother is exemplified.

The basic constitution of this Example is the same as that produced inExample 1, and therefore the description is made noting the differences.

In the final structure of this Example shown in FIG. 6A, the displaypart and the sensor part are formed on one substrate 501, but thecounter substrate 502 of the display part and the counter substrate 503of the sensor part are separated from each other.

In this case, the cell size of the color filter of the sensor part isrequired to be smaller than the cell size of the color filter of theliquid crystal display part, as shown in FIGS. 8A and 8B. In FIG. 5B, acell size 523 of a color filter on a counter substrate 503 of a sensorpart 120 is smaller than a cell size 522 of a color filter on a countersubstrate 502 of a display part 110 in FIG. 8A.

Therefore, it is preferred that the cell size of the counter substrateof the sensor part and the cell size of the counter substrate of theliquid crystal display part are different from each other. Theproduction method thereof may be either a method where a countersubstrate on which color filters having different cell sizes are formedon one substrate is used, or a method where the counter substrate of thesensor part and the counter substrate of the display part are separatelyadhered.

EXAMPLE 3

In this Example, the case where a substrate thinner than the countersubstrate of the display part is used as the counter substrate of thesensor part is exemplified.

The basic constitution of this Example is the same as that produced inExample 2, and therefore the description is made noting the differences.

The constitution of this Example is shown in FIG. 6C.

The thickness of the counter substrate of the sensor part of thisExample is smaller than the counter substrate of the liquid crystaldisplay part and is from 0.1 to 2.0 mm, preferably from 0.1 to 1.0 mm.The line width of the sealing part surrounding the sensor part issmaller than the line width of the sealing part surrounding the liquidcrystal display part (from 1 to 1.3 mm).

The thinner counter substrate of the sensor part in this Example is notlimited to a glass substrate if it is a colorless transparent substrateor a film transmitting light.

By employing such a constitution, the influence on the optical systemattached to the sensor part can be reduced. The thinner the thickness ofthe counter substrate of the sensor part is, the less the light isrefracted, and thus the intensity of light can be maintained to obtain aliquid crystal display panel at low cost, in which the sensor part thathas a small pixel area and can incorporate an image with good quality isformed on the same substrate as the liquid crystal display part.

By making the line width of the sealing part surrounding the sensor partsmaller than the line width of the sealing part surrounding the liquidcrystal display part, the distance between the substrate of the sensorpart and that of the liquid crystal display part are differentiated.

EXAMPLE 4

In this Example, the case where the counter substrate of the sensor partand the counter substrate of the display part are in close contact witheach other by using an adhesive is exemplified.

The basic constitution of this Example is the same as that produced inExample 2, and therefore the description is made noting the differences.

The constitution of this Example is shown in FIGS. 5B and 6D.

By employing such a constitution, the sensor part can be completelyisolated from the external atmosphere, and deterioration due to contactwith the external atmosphere can be prevented. The distance between thesensor part and the counter substrate of the sensor part is from 0 to5_m, preferably 4_m or less, and it is ideal that the counter substrateand the element substrate are in completely close contact with eachother.

EXAMPLE 5

In this Example, an electronic apparatus utilizing the liquid crystalpanel according to the invention is exemplified in FIG. 7. Theelectronic apparatus is a product carrying the liquid crystal panelcontaining an image sensor.

FIG. 7 shows a notebook personal computer, in which the invention can beapplied to a liquid crystal display having an image sensor integratedtherein.

In the invention, because the image sensor is provided on the samesubstrate as the pixel matrix and the peripheral driver circuit,miniaturization and weight saving of the display apparatus having adisplay function and an image pickup function can be realized.Furthermore, because the sensor part and the display part aresimultaneously formed, the display apparatus can be provided at lowcost.

By employing the constitution of the invention, the inclusion of theliquid crystal into the sensor part on the injection step of the liquidcrystal is prevented, and after the adhesion step, the sensor part isprotected from the liquid crystal, dusts and an external impacts. Thus,a durable liquid crystal display apparatus containing an image sensor,in which the sensor part is well operated, can be obtained.

Furthermore, when the optical system is attached to the sensor part, theoptical system can be sufficiently fixed, and the distance between theoptical system and the sensor part can be maintained at a constant valueby the sealing part and the counter substrate. Thus, an image of goodquality with a stable focal distance can be obtained.

1. An electronic apparatus comprising: a first substrate; a displayregion provided on an insulating surface over said first substrate, saiddisplay region comprising an active matrix circuit; an optical sensorregion detecting light provided on said insulating surface over saidfirst substrate; a counter second substrate provided over said displayregion; a counter third substrate provided over said optical sensorregion; a first color filter provided with said counter secondsubstrate; and a second color filter provided with said counter thirdsubstrate.
 2. An electronic apparatus according to claim 1 wherein saidelectronic apparatus is incorporated into a personal computer.
 3. Anelectronic apparatus according to claim 1 wherein said optical sensorregion comprises a switching transistor.
 4. An electronic apparatusaccording to claim 1 wherein said optical sensor region comprises asemiconductor film comprising amorphous silicon.
 5. An electronicapparatus comprising: a first substrate; a display region provided on aninsulating surface over said first substrate, said display regioncomprising an active matrix circuit; a optical sensor region detectinglight provided on said insulating surface over said first substrate; acounter second substrate provided over said display region; a counterthird substrate provided over said optical sensor region; a first colorfilter provided with said counter second substrate; and a second colorfilter provided with said counter third substrate, wherein said secondcolor filter has a cell size smaller than that of said first colorfilter.
 6. An electronic apparatus according to claim 5 wherein saidelectronic apparatus is incorporated into a personal computer.
 7. Anelectronic apparatus according to claim 5 wherein said optical sensorregion comprises a switching transistor.
 8. An electronic apparatusaccording to claim 5 wherein said optical sensor region comprises asemiconductor film comprising amorphous silicon.
 9. An electronicapparatus comprising: a first substrate; a display region provided on aninsulating surface over said first substrate, said display regioncomprising an active matrix circuit; a optical sensor region detectinglight provided on said insulating surface over said first substrate; acounter second substrate provided over said display region; a counterthird substrate provided over said optical sensor region; a first colorfilter provided with said counter second substrate; and a second colorfilter provided with said counter third substrate, wherein said secondcolor filter has a cell size smaller than that of said first colorfilter, wherein thickness of said counter third substrate is smallerthan that of said counter second substrate.
 10. An electronic apparatusaccording to claim 9 wherein said electronic apparatus is incorporatedinto a personal computer.
 11. An electronic apparatus according to claim9 wherein said optical sensor region comprises a switching transistor.12. An electronic apparatus according to claim 9 wherein said opticalsensor region comprises a semiconductor film comprising amorphoussilicon.